>> it's an interfaith service. i expect we will hear from the president like in other services he has attended including tucson and others. the president is a consoler in chief. he does that job very well. many people have commented that he has comforted a lot of families in those situations. when you get to thursday and there isn't a lot of progress on this investigation or there really isn't anything that we're learning, it may be a little awkward as far as questions for investigators as the president is in town. he is there to comfort families and comforted for boston as it moves forward i'm sure from this moment. >> bob: it sounds like these explosives were detonated -- there is so many leg wounds here. they didn't have a large area of coverage of these things. they were on the ground obviously. during the press conference, the f.b.i. counterterrorism person said they were looking at fragments of evidence on roofs of buildings. how does that equate, do you think? >> bret: that is interesting. i don't know. i th